Ore-roasting furnace



(No Model.) 2 Sheets--Sheet 1.

I. B. HAMMOND. ORE ROASTING FURNACE.

No. 404,000. Patented May 28, 1889.

X I V g' WITNESEEE. Ir INVENTEJF {NoModelJ 2 Sheeta-Sheet 2,

I. B. HAM1V[OND. ORE BOASTING FURNAOE.

No. 404,000. Patented May 28, 1889.

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UNITED STATES PATENT OFFICE.

ISAAC B. HAMMOND, OF CHICAGO, ILLINOIS.

ORE-ROASTING FURNACE.

SPECIFICATION forming part of Letters Patent No. 404,000, dated May 28,1889.

Application filed October 1, 1888. Serial No. 286,865- (No model.)

To all whom it 12mg concern:

Be it known that I, ISAAC B. HAMMOND, of Chicago, in the county of Cookand State of lllinois, a citizen of the United States, have inventedcertain new and useful Improvements in Ore-Roastlng Furnaces, of whichthe following is a specification.

My present invention relates to that class of furnaces particularlyadapted for desulphurizing and for manufacturing sulphuric acid fromores of iron, copper, and arsenical pyrites; and it has for its objectto improve 1these furnaces in certain details of construc- Furnaces ofthe above-described class are shown in United States Letters Patent No.248,521 to Peter Spence, and in English Letters Patent No. 64 of 1868 tothe same inventor. In these furnaces the ore to be desulphurized is fedupon the furnace-floor, and is there spread and gradually carried alongto a point of discharge either onto a second floor or outside.

My present improvements relate to the mechanism for so automaticallyraking or spreading and discharging the ore. In these furnaces as nowordinarily constructed a tier of such floors is commonly employed, theore being fed onto the upper one and thence distributedand dischargedover and upon the others successively, as shown in the American patentbefore cited. My improvements are applicable either to such furnaceshaving a plurality of floors or to a furnace having a single floor, asshown in the English patent above mentioned.

In the drawings I have represented my improved raking mechanism in theform now best known to me.

Figure 1 is a plan view of the raking device; Fig. 2, an end elevation;Fig. 3, a side elevation thereof, and Fig. 4 a section on the line as xof Fig. 1.

It is desirable in the operation of desulphurizing that the ore shouldbe fed into the furnace in limited quantities and at regulatedintervals, and that while it is upon the floor of the furnace andsubject to the heat it should be raked or stirred, and also should begradually carried across the floor to the point of discharge.

In the raking devices contained in the patents above mentioned therake-head has had simply a reciprocating motion over the furnace-floor,the teeth of the rake being generally triangular, with the base of thetriangle set toward the place where the ore is to be discharged. Tworows of these teeth have generally been used, the teeth being set in therakehead checker-board fashion or so as to break joints. With such rakesit has been found in practice that all the ore would not be drawn ormoved to the discharge-orifice, but ore would be left at the end of thefloor farthest from the discharge in gradually-increasing quantities,and would there become gradually banked up to such an extent as torequire the opening of the furnace and the raking out of the banked-upore by special devices.

My improved rake, to obviate this defect, is constructed with a doubleor two faced head, II II, each face having teeth I I, of ordinaryconstruction; The rake is hung by means of a cross-shaft, K, betweenslides L L, by which it is adapted to be moved over the furnace-floor.The rods M M, by which power is transmitted to operate the rake, areconnected to the rake-head at a point outside the center of oscillationof the shaft K, preferably to a pair of gudgeons, N N, as shown,extending through slots 0 O in the slides L L, the ends of which slotsact as stops to limit the radial motion of the gudgeons, andconsequently of the swinging rake head. These slots are to be of alength sufficient to permit the rake-head to swing from the position inwhich one face with its teeth is in contact with the ore to that inwhich the teeth of the other face are similarly brought in contact withthe ore.

From this construction it will be seen that when the rake is moving inone direction the rearinost face, as H, with its teeth is in contactwith the ore. \Vhen the limit of motion is reached and the return motionof the rods M M commences, its first effect is to rock the rake-head andbring down the farther face, H, into position to rake the ore, but at apoint beyond the extreme range of the face H and consequently beyond theore which the teeth of the face may have carried forward. The gudgeonsnow bringing up against the end of the slot, the rest of the motion ofthe rods carries the rake backward toward the discharge-orifice andcauses a certain portion of the ore to be discharged through the same.In this way the face of the rake which acts during its motion toward thedischarge-orifice being always beyond the farthest body of ore, noportion of the latter can get beyond the range of the rake in returning,and thus the banking up of the ore is prevented.

The rods M M, which for convenience are duplicate, as shown, extendoutwardly beyond the face of the furnace-wall and are connected with anysuitable source of reciprocal or in-and-out motion. lhismotion,which, asis well known, should be quite slow, may be constant or may beintermittenti. e., the rake may remain at rest for a time after it hasfinished each complete course backward and forward through the furnace.

I do not wish to be understood as claiming herein, broadly, rakingdevices for ore-furnaces, as devices for those purposes have been longknown.

A rake having a two-faced swinging head is not broadly new with me, thesame being shown in United States Letters Patent No. 80,065. In thatpatent, however, and in all structures heretofore used, so far as I amaware, the rake-rods are connect-ed to the swinging head at its centerof oscillation, and therefore cannot be utilized to oscillate or swingthe head. By my improvement, however, the rake-rods being connected tothe swinging head at a point outside the center of its swing, I amenabled to oscillate the head by means of the rake-rods alone. I am thusenabled to dispense with the additional devices for this purposeheretofore employedas, for example, in the patent above mentioned, inwhich the head is oscillated by means of extensions projecting up andengaging with the end walls of the furnace. By doing away with theseadditional parts the structure is materially simplified and improved.

I claim- A sliding rake for ore-furnaces, having a double or two facedswinging head, each face being provided with suitable teeth, the saidhead being pivotally connected to the rakebody, rake-rods connected tothe said swinging head outside the center, around which it swings, andstops, substantially as described, to limit the extent of swing of thehead to bring one or the other of the rake-faces in working contact withthe ore, substantially as and for the purpose set forth.

In testimony whereof I have hereunto subscribed my name this 21st day ofSeptember, A. D. 1888.

ISAAC B. HAMMOND.

Vitnesses:

JOHN H. TAYLOR, ELLEN B. ToMmNsoN.

